In this study, the methanol extract of bark of Cordia dichotoma Forst., belonging to the family Boraginaceae was prepared by successive extraction procedure ( petroleum ether, ethyl acetate, methanol) in soxhlet apparatus and subsequently, the extract was evaluated for its phytoconstituents and pharmacological activity. Comparatively, higher yield (7.11%) of methanol extract was obtained. Phyto...

We report the first isomeric selective kinetic study of the dominant isomeric pathway in the OH initiated oxidation of 1,3-butadiene in the presence of O(2) and NO using the laser photolysis-laser induced fluorescence (LP-LIF) technique. The photodissociation of the precursor 2-iodo-but-3-en-1-ol results exclusively in the dominant OH-butadiene addition product, permitting important insight int...

To determine the significance of germination on phytochemical constituents and non-enzymatic antioxidant activities of Ceiba pentandra seed extracts. Phytochemicals and antioxidant activities of raw and germinating seeds of Ceiba pentandra were estimated by different methods. The levels of phytochemical constituents were influenced by germination and increased except alkaloids and tannins, whic...

Ozone is produced in the troposphere by gas-phase oxidation of hydrocarbons and CO catalyzed by hydrogen oxide radicals (HOx ≡ OH + H + peroxy radicals) and nitrogen oxide radicals (NOx ≡ NO+NO2). Heterogeneous chemistry involving reactions in aerosol particles and cloud droplets may affect O3 concentrations in a number of ways including production and loss of HOx and NOx, direct loss of O3, an...

Free radicals are involved in the process of lipid peroxidation and play a cardinal role in numerous chronic diseases like cancer, coronary heart disease and ageing. Thus the ability to scavenge free radicals in order to minimize oxidative damage to living cells is very important. The hexane extract of Acalypha hispida (Burn F.) was screened for phytochemical constituents and was found to conta...

Relative rate techniques were used to study the kinetics of the reactions of Cl atoms and OH radicals with ethylene glycol diacetate, CH3C(O)O(CH2)2OC(O)CH3, in 700 Torr of N2/O2 diluent at 296 K. The rate constants measured were k(Cl + CH3C(O)O(CH2)2OC(O)CH3) = (5.7 +/- 1.1) x 10(-12) and k(OH + CH3C(O)O(CH2)2OC(O)CH3) = (2.36 +/- 0.34) x 10(-12) cm3 molecule-1 s-1. Product studies of the Cl a...

Small aldehydes are formed during the photochemical oxidation of many VOC’s, olefins and terpenes in urban as well as in rural areas. Photolysis and reaction with the OH radical are the most important initiation reactions for the removal of these compounds conducting to the formation of peroxy radicals and in the case of photolytic decomposition, either to stable molecules or free radicals. The...

Introduction Conclusions References Tables Figures ◭ ◮ ◭ ◮ Back Close Full Screen / Esc Abstract Introduction Conclusions References Tables Figures ◭ ◮ ◭ ◮ Back Close Full Screen / Esc Abstract This work details the first direct observation of OH as a product from (R1): HO 2 +CH 3 C(O)O 2 → (products), which has generally been considered an atmospheric radical termination process. The technique...

The nitrogen and oxygen isotopic composition of nitrate in ice cores offers unique potential for examining reactive nitrogen oxide (NOx) budgets and oxidation chemistry of past atmospheres. A low-latitude record is of particular interest given that the dominant natural sources of NOx and production of hydroxyl radical are most prevalent in the tropics. Any interpretation of nitrate in ice cores...